It is commonly known that constrictions in blood vessels can lead to heart problems. As a result, patients are generally urged to exercise and maintain a proper diet in order to avoid debilitating obstruction of the blood vessels. Opening of constricted blood vessels has been a problem to the medical profession for many years. It has been proposed that catheters provided with rigid dilator devices or balloon dilators or heated balloon dilators be inserted in blood vessels to enlarge the fluid passageway in constricted blood vessels.
An example of one prior art device is found in U.S. Pat. No. 4,709,698 to J. H. Johnston et al. (dated Dec. 1, 1987) which discloses a heatable dilation catheter. This prior art catheter is provided with an inflatable balloon with heating elements attached to it. The catheter is inserted in a blood vessel, and the balloon is expanded to dilate the vessel in the area of the obstruction. The heating elements are used to treat the vessel wall tissue to give it a hardened, leathery consistency to cause the vessel wall to retain the expanded dilated configuration. The treatment of the vessel wall is accomplished by applying electrical current directly to the tissue. Heating element electrodes of opposite polarity are placed in contact with the tissue in the area to be treated causing the tissue to be heated by current flowing between the electrodes. This and other prior art approaches to the problem of constricted vessels have the serious disadvantage that the dilating action forces the offending matter aside without removing the obstructing matter from the vessel. The result is that constrictions recur in the same areas and require repeated treatments to provide an adequate passage.